I understand your point of view and I think the best providers won't ask for stats but there are some providers who can't perform with them and would rather not get their money.
We had an Annapolis escort who said in his ad "no blacks", I stayed away from him.
A frequent poster started a thread proclaiming he wouldn't date, have or hire "men of color". I don't know why folks think that way but that's what it is.
That's why I always hire gay men! I don't want to pay for someone who is thinking of a woman when he's with me... Besides when I served I had plenty of sex with truly straight men.
The secret is NOT making it look as if it's all about the $. Good escorts accomplish it!